Side Show BY DENNIS BROWN
Here's good news for prospective Muny ticket buyers. This week's offering, Side by Side by Sondheim, is sure to be the season's slowest-selling show. Yet at its best, this musical entertainment (which was first produced in London 27 years ago) might well prove to be the most intelligent and stylish offering of the entire summer.<br /> <font size="1" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular" color=#9c0031">W…